Aswath Damodaran 185
Measuring Returns Right: The Basic Principles
! Use cash flows rather than earnings. You cannot spend earnings.
! Use “incremental” cash flows relating to the investment decision, i.e.,
cashflows that occur as a consequence of the decision, rather than total cash
flows.
! Use “time weighted” returns, i.e., value cash flows that occur earlier more
than cash flows that occur later.
The Return Mantra: “Time-weighted, Incremental Cash Flow Return”
These are the basic financial principles underlying the measurement of
investment returns.
We focus on cash flows, because we cannot spend earnings.
We focus on “incremental” effects on the overall business, since we
care about the overall health and value of the business, not individual
projects.
We use time-weighted returns, since returns made earlier are worth more
than the same returns made later.